I just finished writing an article about Facebook applications that gave me the opportunity to test a large number of the less-used apps on the platform. This broad view left me with some new insights into what makes a good Facebook application (as opposed to a mediocre or crappy one, and believe me, there are a lot of those).

If you’re thinking about building a Facebook app, here are 10 things you can do to make sure that yours stands out from the crowd:

1) Make it fun. Whether you’re building a game or a tool, always keep in mind that the people who are using Facebook are usually doing so on their free time. Most of them are under 35. Most of them are using Facebook for entertainment. So keep things fun. FedEx did a great job of this when they built Launch a Package, which lets users send each other packages – using a springy slingshot. Sending a package via a slingshot that bounces around is a whole lot more fun than sending something with the click of a button.

2) Give it some substance. The programming behind an application may be rock-solid, but without substantive content surrounding the application, it will fall flat. Every application should have at least:

A landing page that provides clear branding

Easy-to-understand instructions about how to use the application or play the game

Multiple options for use, such as various “rounds” or “levels”

Enough content to engage a user for at least 10 minutes at a given time

A summary/analysis area that lets the user see their history with the application

3) Make it look nice. There are currently more than 27,000 applications on Facebook. Yours will have some competition. If a user is going to choose between two applications that do similar things, they will likely pick the one that is more visually appealing. Take a look at Where I’ve Been vs. Travel Buddies. Which are you more likely to use?

4) Include music or sound effects. Facebook is a multimedia platform – take advantage of it. All of the best applications have somehow incorporated sound effects or music. This doesn’t have to be fancy – Traveler IQ Challenge uses the sound of a ticking clock very effectively.

5) Provide a takeaway. When the user has finished using the application, they want something to show for it – either a ranking, a rating or an embeddable object. If you build a game, provide a ranking system that lets users compare themselves to each other. If you build a test, give them a score. Or if you have a graphical application, give them a downloadable picture that they can use on Facebook, but elsewhere, too. This is what Sketch Me does – it turns a profile picture into a pencil drawing that can be saved and used anywhere the user chooses.

6) Make the user want to share the app (as opposed to have to share it). Because of the social nature of Facebook, applications that are developed for the platform should all be sharable. But don’t force your users to share the app to continue using it. The best applications provide an easy way to share, but don’t force users to “send this to 8 friends NOW!” If you build a good app, people will want to share it.

7) Do something different. With thousands of applications already in existence, there is a lot of duplication. But with a little creative thinking, something that already exists can be made new again. Although there are many IQ test apps on Facebook, Who Has The Biggest Brain? stands out because of its use of “size of brain” as a ranking system, and the way that it measures the four areas of intelligence in a game show format. The idea for the application doesn’t have to be completely original, as long as there is something unique that sets it apart.

8) Use solid programming. Your application has to work, and has to work seamlessly. Take the time to understand the Facebook developer platform. If you’re not a developer, work with one who is a Facebook specialist. Make sure that the programming behind the application is solid. The time that you take to really get to know the platform will pay off – this link has some fantastic resources.

9) Put ulterior motives out of your mind. Many Facebook apps are obviously trying to get the user to do something other than use the application – click an ad, download a companion application, buy something, etc. When building an application, first make something that people will want to use. Developing a great classified application will be easier than developing a great classified application that will ALSO get someone to download your shopping app. By focusing on the first objective, you’ll create something of value that will generate a large audience – to which you can later market your shopping application.

10) Do the “addiction test.” Can someone use your application once and then never again? Not good. Do they use it once and then feel compelled to immediately use it again? That’s good. Do they want to go back and use it the next day? And the next? That’s even better. Creating an application that can be used time and again is the ultimate goal for killer Facebook app development. One way you can test for this is to ask people you know to use the app. See if they mention the word “addiction.”

If we are talking about some amazing applications of Facebook i would like to share an application which i came across when i was surfuing net. This application is full of fun. With the help of this application you can add movie messages to your photo. yes the application named Movie Message allows you to listen to thousands of lines from Hollywood’s greatest movies and share them with your Facebook friends. Add a personal message or just let your favorite actor say it for you.

[…] 10 tips for building a killer Facebook app (6/5/08) “Do the “addiction test.” Can someone use your application once and then never again? Not good. Do they use it once and then feel compelled to immediately use it again? That’s good. Do they want to go back and use it the next day? And the next? That’s even better.” […]